Method and apparatus for slitting paper webs



June 27, 1961 R. REME R 2,989,882 A METHOD AND APPARATUS FOR SLIITINGPAPER WEBS Filed Sept. 11, 1956 F'IEA- Patented June 27, 1961 2,989,882METHOD AND APPARATUS FOR SLI'ITING PAPER WEBS Robert K. Remer, Elgin,Ill., assignor to Tribune Company, Chicago, Ill., a corporation ofIllinois Filed Sept. 11, 1956, Ser. No. 609,215 14 Claims. (Cl. 83-13)This invention relates to the production of paper such as newsprint inpaper mills, and more particularly to the slitting of the web prior towinding it into rolls. In normal methods of slitting a great deal oflint and dust is created which deposits on the web, in the form offiber, fuzz, or whiskers. Such extraneous material often gathers intowads forming What are known as hickies on the paper sheet. These canseriously mar the printed surface, particularly in the case of ofi'setprinting, since the hickies can be transferred to the blanket and in theprinting process the imperfection in the printing resulting therefromwill be repeated on sheet after sheet in the same place. Thisnecessitates frequent cleaning or washing up of the blankets, plates andink rollers, with consequent loss of time and increase in labor.

Some mills use compresed air, a vacuum or a brush to remove the dust andlint from the paper, but due to the high static charge which usuallyexists on the paper, there is a tendency for dust particles or lint tostick to the surface so that they are not effectively removed byexisting methods. I have provided means and a method for reducing oreliminating the static as set forth in my application, Serial No.612,081, filed September 11, 1956, and this tends to alleviate theproblem to some extent. However, the problem could be prevented fromarising or greatly minimized if the formation of lint and dust in theslitting of the paper could be prevented, and it is accordingly thepurpose of this invention to accomplish this result.

In accordance with the invention, I apply to the knives used forslitting the paper a non-friction lubricating solvent, in vapor form,which is redeposited on the slitted edge of the paper and plasticizesthe edge so as to hold the lint, fuzz or whiskers in the sheet ratherthan allowing them to fly into the air and become trapped between thesheets as they are wound onto the customary web roll.

(It is generally understood that paper in its natural state posseses anexcess of electrons, and thus is negatively charged. In the usual courseof conducting a paper web through a slitting or cutting machine at highspeeds, the friction of the paper being drawn over rollers in such amachine creates kinetic electricity in the paper web tending to increasethe naturally existing negative charge carried by the paper web. Sincedust is naturally attracted to negatively charged bodies, the lint, dustand fuzz formed by slitting the paper web is strongly attracted to thepaper web.

The chemicals used to produce the vapor in this paperslitting processhave anti-static properties as will hereinafter more fully appear.

The invention resides primarily in the method whereby the formation ofslitter dust or fine fibers which tend to deposit themselves on the webis prevented, but a secondary object of the invention is to provide anapparatus which is particularly well adapted to this purpose.

Other objects and advantages of the invention will be apparent from thefollowing description, taken in connection with the accompanyingdrawings, in which:

FIG. 1 is an elevational view, partly in section, of my apparatus,showing the manner in which the method of the invention may be carriedout; and

FIG. 2 is a top plan view thereof.

As shown in FIG. 1, the web is passed through a slitter comprisingshafts 11 and 12 on which two pairs of slitter knives are carried. Theknife 15 of one pair (shown at the right in FIG. 1) is secured to theshaft 12 by means of a hub 13 and set screw 14. The other knife,identified by the numeral 18, of this pair is secured-to the shaft 11 bymeans of a hub 16 and set screw 17. The knives of the other pair aresimilarly attached to said shafts, such knives and their hubs and setscrews being identified by similar numerals with prime markings. Thepairs of knives are suitably spaced to obtain the desired width of websfor winding into the customary newsprint rolls for newspaper printing,it being understood that the paper is produced in the mill on widescreens and felts resulting in a web of greater width than that desiredfor the rolls on which the paper is wound for shipment and for handlingin the newsprinting operations.

Beneath the right-hand pair of knives (viewing FIG. 1), I provide avaporizing chamber, generally identified by the numeral 19. A secondvaporizing chamber is pro vided beneath the pair of knives 15', 18, andsince this chamber is identical to the chamber -19, the parts areidentified with the same numerals but with prime markings. Therefore,for the most part, one unit only will be described, but it will beunderstood that the description applies in the same manner to the otherunit except where otherwise indicated.

The chambers 19 and 19 are supported beneath the slitter by any suitablemeans (not shown).

Water is supplied to the chamber 19 through a pipe 20 having a T-joint21 therein connecting the same through a valve 22 with a water inletpipe 23. A valve 24 is also provided in the pipe 20.

When the chamber 19 has been filled to desired level, the valve 22 isclosed. Cationic chemicals, to be hereinafter described, are added tothe water by placing the same in the chamber 19 before or after thewater is admitted.

A headspace is provided in the chamber 19 above the liquid level and anopening 26 is provided in a cover 40 for said chamber. Said opening 26is in the form of a narrow slit with flanges 41 extending upwardly fromthe cover at the edges of said slit. The knife 15 is disposed in theslit 26, as shown in FIG. 1 of the drawings.

In order to normally keep the liquid at substantially the same level inthe two chambers, standpipes 27 and 27 are provided in said chambers,respectively, and are supported by an interconnecting pipe 29 in whichvalves 28 and 28' are provided. Also upwardly-turned overflow pipes 32and 32 are provided in the chambers 19 and 19', respectively, atsubstantially the desired liquid level.

A heating element 30 is provided in the bottom of the chamber 19 and isconnected with a suitable source of electrical energy by wires 31. v

A conductor member 33 extends through the wall of the chamber 19 intothe solution 25 and has a wire conductor 34 leading therefrom throughwhich any static charges formed within said chamber will be dissipated.

Provision is made for admitting steam to the chambers 19 and 19' throughthe pipes 20 and 20 after the water valves 22 and 22' have been closed.A valve 35 in a pipe 42 leading from a source of steam (not shown) isprovided for controllingthe admission of the steam.

An extended part of the pipe 20 is connected with the pipe 20 by meansof a T joint 36 so that the steam may be admitted to both chambers fromthe pipe 42 through the valve 35.

The heating of the solution 25 in the vaporizing chambers causes theformation of vapor 38 in the upper part of the chambers and the knives15 and 15', which rotate in this vapor in the slits 26 and 26', becomethoroughly coated with the vapor and/or its condensate, which istransmitted to the paper as the knives cut therethrough and to theco-acting knives 18 and 18'. By virtue of the vapor being positivelycharged and the paper negatively charged, the vapor and/or itscondensate is easily deposited upon the edge of the paper, where itplasticizes gile paper and prevents the formation of lint, dust and 22.While a number of positively charged or cationic chemicals will serve toprovide a proper solution for the vaporizing chambers, the following maybe given as examples: quaternary fatty amines such as Armac C;quaternary ammonium compounds such a cetyl pyridinium chloride; andSapamine WL which is an aliphatic tertiary ammonium acetate compound. Itshould be noted that Armac C is a trade name by which the manufacturer,Armour Chemical Division, identifies the acetic acid salts of its fattyamines, which salts may be represented by the formula:

in which R represents an alkyl group, derived from fatty acids,containing 8 to 18 carbon atoms. Polyethylene glycols such as Carbowax1000, 2000, 4000 or 6000 may desirably be used as plasticizers in thesolution.

A proper solution for use in the practice of my method may consist ofwater containing from 1% to 20%, by volume, of a cationic chemical, suchas one of those mentioned above.

The heating of the solution and the admission of the steam to thechambers 19 and 19 create the vapor indicated at 38 and 38', throughwhich the knives 15 and 15', respectively, rotate.

Since certain changes can be made both in the procedures and theapparatus above described without departing from the spirit or scope ofthe invention, it is intended that the disclosures herein shall beinterpreted as illustrative and not in a limiting sense.

I claim: I

1. A method for slitting paper comprising applying to said paper as itis cut an organic cationic chemical fluid so as to prevent the formationof loose fibers, lint or fuzz.

2. A method for slitting paper comprising vaporizing a solutioncontaining an organic vaporizable cationic chemical and applying theresulting fluid thus formed to the paper as it is cut to prevent theformation of loose fibers, lint or fuzz.

3. A method for slitting paper comprising vaporizing a solutioncontaining an organic vaporizable chemical and coating the blades usedto slit said paper with the resulting fluid so that such fluid istransferred from said blades to the paper as it is cut, thus preventingthe formation of loose fibers, lint or fuzz.

4. A method of slitting paper comprising vaporizing a solutioncontaining an organic vaporizable cationic chemical and coating theblades used to slit the paper with the resulting fluid so as to preventsaid blades from creating static electricity as the paper is slit.

5. A method for slitting paper without forming lint or dust, comprisingvaporizing a solution containing an organic vaporizable cationicchemical and applying the resulting fluid to the paper as it is cut. I

6. A method for slitting paper without forming lint or dust, comprisingvaporizing a solution consisting of water containing from 1% to 20% byvolume of a vaporizable organic cationic chemical and applying theresulting fluid to the paper as it is cut.

7. A method of slitting newsprint which comprises passing a. web thereofto be slit between cutter blades andcontinuously applying to such bladesa vapor of an organic vaporizable cationic solution.

8. A method of slitting newsprint which comprises passing a web thereofto be slit between cutter blades as at least one thereof is rotated in avapor bath produced by heating an organic vaporizable cationic solution.

9. A method of slitting newsprint which comprises passing a web thereofto be slit between cutter blades as at least one thereof is rotated in avapor bath produced by heating and injecting steam into an organicvaporizable cationic solution.

10. A method of slitting paper which comprisespassing a web thereof tobe slit between cutter blades as at least one thereof is rotated andcoating a rotating cutter blade with vapor formed by heating andinjecting steam into an organic vaporizable cationic solution.

11. In combination with a paper web slitter having rotating cutterblades, an apparatus for coating the blades of the slitter with vaporfrom a cationic solution, comprising: a vaporizing chamber forcontaining said solution, a heating unit arranged to heat the solutionin said chamber, said vaporizing chamber having a narrow opening in thetop thereof into which one of said rotating blades of the slitter mayextend and pass through the vapor formed in the chamber, whereby acoating adapted to counteract the formation of static will be applied tosaid blade and by it to the web.

12. In combination with a paper web slitter having rotating cutterblades, an apparatus for coating the blades of the slitter with vaporfrom a cationic solution, comprising: a vaporizing chamber forcontaining said solution, means for introducing water into saidvaporizing chamber to form the solution, a heating unit arranged to heatthe solution in said chamber, said vaporizing chamber having a narrowopening in the top thereof into which one of said rotating blades of theslitter may extend and pass through the vapor formed in the chamber,whereby a coating adapted to counteract the formation of static will beapplied to said blade and by it to the web.

13. In combination with a paper web slitter having rotating cutterblades, an apparatus for coating the blades of the slitter with vaporfrom a cationic solution, comprising: a vaporizing chamber forcontaining said solution, means for introducing water into saidvaporizing chamber to form the solution, a heating unit arranged to heatthe solution in said chamber, means for injecting steam into thesolution to further heat and vaporize the same, said vaporizing chamberhaving a narrow opening in the top thereof into which one of saidrotating blades of the slitter may extend and pass through the vaporformed in the chamber, whereby a coating adapted to counteract theformation of static will be applied to said blade and by it to the web.

14. A method of slitting paper wherein the slitting blades are caused tobe coated with a vapor formed from a heated solution comprising watercontaining a cationic chemical taken from the group consisting ofquaternary fatty amines and quaternary ammonium compounds.

References Cited in the file of this patent UNITED STATES PATENTS341,895 Edmunds May 18, 1886 1,036,173 Arey Aug. 12, 1912 1,368,933Hutchinson Feb. 15, 1921 1,472,450 Yetter Oct. 30, 1923 2,067,174 Dickieet a1 Ian. 12, 1937 2,393,863 Myers Jan. 29, 1946 2,421,363 Young May27, 1947 2,658,427 Doot Nov. 10, 1953 2,668,785 Jefierson et al. Feb. 9,1954 2,729,576 Trusler Jan. 3, 1956

